摘要:

AbstractTWO fabrics are shown to occur in the surface block layers of periglacial blockstreams on Mt. Barrow, Tasmania. The most common of these comprises a pole aligned along the slope orthogonal with an upslope imbrication; this may be somewhat complicated by a secondary, cross-slope maximum. The second fabric has an isotropic orientation pattern and involves generally low inclination values. The difference between these and variations in the strength of the first are thought to reflect the slow response of the block material to the stresses involved in solifluction. Downslope distance is, therefore, of basic importance in accounting for the fabric of the material at any single point. The two fabrics may also be used to define the difference between autochthonous and allochthonous blockfields.

ISSN:0435-3676    

DOI:10.1080/04353676.1968.11879783

出版商:Taylor&Francis    

年代:1968

数据来源: Taylor

摘要:

AbstractSuperimposition to the ground beneath of meltwater streams flowing supraglacially and englacially has recently received increasing attention in Britain as an important method of meltwater channel formation (Price 1960; Embleton 1961; Sissons 1963; Bowen and Gregory 1965). Detailed mapping in the east Cheviot area (Fig. 1) by the writer, in conjunction with observations in northeast Scotland, suggests that the majority of glacial meltwater channels in these areas can be satisfactorily interpreted by the superimposition hypothesis and that underlying topography considerably influenced the development and form of these features.

ISSN:0435-3676    

DOI:10.1080/04353676.1968.11879784

出版商:Taylor&Francis    

年代:1968

数据来源: Taylor

摘要:

AbstractCorries are taken as an example of a glaciated landform. The preliminary aim is to find a simple curve to describe the general shape of the corrie longitudinal profile. These curves are useful to separate true corries from other mountain hollows. Types of deviations from the ideal curves can be pinpointed and analysed. Several types of curve are investigated. The previously used arc of a circle is generally unsatisfactory. A logarithmic curve which fits 81% of the corrie sample is a simpler means of comparison. The great similarity between corries must be due to the effect of glacial flow patterns, but variations within the prescribed morphological limitations are clearly related to structure. Its influence on the backwall foot area and the floor is discussed. In both, glacial processes and structure are linked in a complex manner. Reverse slopes are developed only where rock structures permit.‘Schrundline’corries also appear to be related to a special combination of joints. This particular type of corrie is comparatively rare, as are many text-book land-forms.

ISSN:0435-3676    

DOI:10.1080/04353676.1968.11879785

出版商:Taylor&Francis    

年代:1968

数据来源: Taylor

摘要:

AbstractSediment cores were collected from 18 lakes on Bjørnøya at different altitudes between 10–100 m a.s.l. Four cores were analysed in greater detail for pollen and diatoms, and radiocarbon analyses were made on three horizons in one of the cores. In most cases, the sediment sequence consisted of a bed of 1–3 m of silty lake muds underlain by thin layers of silts and clayey silts of lacustrine or sterile character. A tripartite pollen stratigraphy could be established, and the cores were correlated on this basis. The transition from the basal silts to the muds appears more or less synchronous in all the cores and probably reflects the end of glacial conditions on the island. An age of about 10.000 radiocarbon years is suggested for this. As only lacustrine deposits were formed in the basins investigated, very little, if any, negative shore-line displacement can have occurred on Bjørnøya since the deglaciation.

ISSN:0435-3676    

DOI:10.1080/04353676.1968.11879786

出版商:Taylor&Francis    

年代:1968

数据来源: Taylor